Telephone system



W. T. BOOTH.

TELEPHONE SYSTEM. A`P1f1|cAT1oN FILED MAR.19.1918.

Eatented Aug. 99 19211 STATS narra WENT @'FFHQ.

WILLIAM T. BOOTH, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Aug. 9, 19211.

Application led March 19, 1918. Serial No. 223,333.

To all whom t may concern.'

Be it known that I, IVILLIAM T. BOOTH. a citizen of the United States, residing at East Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems, and more particularly to a system in which a number of stations are arranged in a plurality of `different groups for group operation.

The principal object of the present invention is to provide a system in which a station associated in one group can be readily disconnected therefrom, and associated with another group without affecting the current supplied to such station. In accordance with this feature of the invention means are provided to maintain the operating current supplied to such station substantially the same, irrespective of the disconnection of such station from one group, and the connection of such station for operation with another group, and in the provision of switching arrangements to effect the transfer of such station from one group to an-A other.

Another feature of the invention resides yin the provision of a system in which a station may be associated with another group of lines for telephone operation therewith without affecting the current supplied to the different stations comprising the group from which such station was disconnected, and to which it was transferred. In accordance 4 with this feature of the invention, means are provided to maintain the operating current supplied to each of the stations of such groups substantially the same irrespective of the disassociation of a station from one group, and the connection of such station for operation with another group and in the provision of switching arrangements to effect the transfer of such station from one group to another.

The drawings diagrammatically illustrate one embodiment of the present invention as applied to a telephone system, two groups of lines being deemed suflicient to an understanding of the invention, although such a system may include a number of additional groups therein, if desired.

In the drawings, while only two lines of each of these groups have been shown, they may comprise a greater or less number of lines; and the number of lines normally'associated in any group may be independent of the number of lines normally associated with any other group. The groups are indicated as I and II and each group comprises stations A and B. The complete circuit arrangement of the stations has been shown only for station B of group I and station A of group II, but the circuits of the other stations of these groups would be similar thereto.

The system is provided with a pair of conductors 10, 10', common to all the stations of the system and connected to a battery 11, which serves as a source of talking current for the system. Each of the group stations has a pair of conductors 12, 12', connected to the conductors 10, 10 respectively, which extend through respective windings of an impedance coil 13, individual to each station, to the second and third contacts of a four-blade-single-throvv switch 14. The resistance of thel windings of the coils 13 is elfective in regulating the amount of direct current supplied to its respective station from the battery 11. A fourspring jack 15 is also provided for each station and has the contact springs normally separated as shown. The ring spring 16 of each of these jacks yis connected to a respective conductor 12 intermediate its respective impedance coil 13 and switch 14 by a conductor 17, while the tip spring 18 thereof is similarly connected to its respective conductor 12 by a conductor 19. Under these conditions the battery potential at the second and third contacts of switch 14 at any station, will bey substantially the same at the ring and tip springs of the jackl thereof, although the battery circuit to the station will not be completed until closure of the switch 14 or jack 15, of such station as hereinafter eX- plained.

Each station is shown as provided with a pair of line conductors 20, 20', and with a receiver 21 and transmitter 22 for operable association with such line conductors. In the present case the receiver 21 is shown as bridged across these conductors, and the transmitter 22 vnormally disconnected therefrom by a key 23. This key, in normal position, provides a. parallel circuit with the re-f ceiver 21 across the conductors 20, 20', which circuit includes a resistance 24, and the -key when operated connects the transmitter 22 across the line conductors in parallel with the receiver and opens the circuit through v the resistance 24. The resistancev 24 used would preferably have a value equal to that of the resistance of the transmitter 22 associated therewith so that the transmission efficiency of the station will be the same irrespective of whether the transmitter thereat is connected in circuit. The particular arrangement of the receiver and transmitter ofthe stations, however, forms no part of` the present invention and the invention is not restricted to such arrangement, inasmuch as it is obvious that the arrangement by which a station normally in one group can be disconnected therefrom and connected to another group without affecting the current supplied thereto, is independent of the particular arrangement of the receiver and transmitter of the station.

The line conductors 20 and 20 of each station are connected respectively to the first and fourth contacts of the switch 14 and also multiplied, through conductors 25 and 26, respectively, to the respective springs 27 and 28 of the jack 15 thereof. The first and secl ond, and the third and fourth blades of each switch 14 are multiplied together, the first pair being connected to a conductor 29, and the second air being connected to a conductor 30. hese conductors 29 and 30, in the case of the stations of group I, are connected to group conductors 31 and 31 re. spectively,` which are common to al1 the stations of that group, while the conductors 29 and 30 of the stations of group II are connected to similar group conductors 32 and- 32 common to the stations of group II.

f or convenience in interconnecting one group with another group, each set of group -conductors may have one or more switches 33 associated therewith, together with a like number of pairs of connecting conductors 34, .34. Closure of the group switches 33,

i individual to groups which it is desired to associate4 together, effects the association thereof through the connecting conductors "344 and 34.

This method of associating groups together is merely illustrative since a variety of other arrangements can also be used to accomplish this result.

'The switches 14, jacks 15, and cross connecting switches 33 are preferably arranged on a switchboard at some convenient point and connections made as desired by an operator thereat. lAny suitable system could be provided to signal this operator and indicate the station signaling, but as the present invention is independent of the signaling system, none has been illustrated. Assume, however, that the operator receives av signal from station B of groupk I.y An operators set 35 suitable for use with this system and provided with a plug 36 to engage th,ejacks 15, would be connected Awith the jacku v`15 of such station, therebyclosing the normally open contacts of the jack and connecting battery to station B of group I. The circuit therefor extends from battery 11, conductor 10, .conductor 12 of station B of grou I, upper winding of coil 13, conductor 1 ring spring 16 and alternate contact 27 of jack 15, conductors 25, 20, in parallel through receiver 21, and through ke 23 and transmitter 22 (since the party at would have operated the key 23 under these conditions), thence over conductors 20', 26, alternate contact 28 and tip spring 18 of jack 15, conductor 19, lower winding of coil 13 and conductors 12 and 10 to the other side close the switches 14 of these stations and.'

signal station A in any desired manner. T he operator would under these conditions disconnect his set from the jack 15, thereby returning the latterv toi normal position as shown. Closure of the switches 14 of stations A and B of group I, completes a circuit for each of the stations the same as that previously traced for station A, except that instead of extending through the 'jack'15 it will. now extend from conductor 12 to conductor 20 through the second contact, second and first blades and first contact of switch 14 and from conductor 12 to conductor 20 through the third contact, third and fourth. blades and fourth contact of this switch. Each station, is thus independently supplied with talking battery while the conductors 29 and, 30 of` these stations,extend ing from conductors 20 and 20', respectively, to the group 4conductors 31., 31, complete a telephonie connection betweenthese stations.

Should it'fbe desired to connect one or more stations in-onegroup .with one or more stations in, another group, in this case the' switches 14-of all such- .stations would be operated, and also the switches y33 individual to the two groups between which association was desired. The operation of the switches 14 would serve to telephonically connect the desired stations of each group to their respective group conductors while the operation yof the switches 33 similarly connects the diii'erent pairs of group conductors together through the group connecting conductors 34 and34.

The stations 'are so arranged that closure of the switch 14 of any station will connect that station with the conductors of the group to which 'it is normally assigned but it is often desira'ble to temporarily associate a station with a different group than the one to which it is normally assigned. This is accomplished by providing `a connecting cord, having a pair of conductors 41 and 41 and carrying a plug 42 at each end thereof.

Assuming that it be desired to temporarily associate station B of group I with group II; the switch 14 of station B of group I would be opened, disconnecting station B from the group conductors, and a plug 42 of a connecting cord inserted in the jack 15 of such station, thereby completing the battery circuit thereto as previously explained. The other plug 42 would be inserted in the jack 15 of a station, such as station A in group II (the switch 14 of which would be closed), to connect station A with the group conductors 32, 32 of group' II. Under these conditions station B obtains the same amount of current as it would on association with group I, and the'amount of current supplied to station A of group II and to other' stations of both groups will be substantially the same after association of station B with group II as it was before such transfer was made.

The insertion of the plugs 42 in the jacks 15, in addition to completing the battery circuit of station B, alsoprovides a telephonie connection between conductors 20, 20 of station B and conductors 20, 20', respectively, of sation A. In the case of conductors 20, it extends from conductor 20 of station B, over conductor 25, contacts 27 and 16 of jack 15 of station B, ring contact of upper plug 42, conductor 41, ring contact of lower plug 42, contacts 16 and 27 of jack 15 of sta-tion A in group II, and conductor 25 to conductor 2O of station A. For conductors 20', it extends from conductor 20 of station A, over conductor 26, contacts 28 and 18 of jack 15 at station B, tip contact of upper plug 42, conductor 41', tip contact of lower plug 42, contacts 18 and 28 of jack 15 of station A, and conductor 26 to conductor 20 of station A. 1With the switch 14 of station A closed, this station will be connected to the conductors 32, 32 of group II, while station B, now being in telephonic connection with station A, is also telephonically associated with the group conductors of group II, although still deriving its battery the same as if still connected with group I.

Inasmuch as an additional circuit for the supply of 'battery to station A of group II is provided on closure of the contacts 18, 28

and 16, 27 on insertion of a plug into the lj ack 15 of this station, a station in one group can be telephonically connected directly with a station in another group, if desired, by the connecting cord by inserting the plugs 42 thereof into the jacks 15 of such stations; the switches 14 of such'stations being maintained in open position under these circumstances, therebyl disconnecting the stations from the group conductors thereof. This method is also somewhat simpler where but two stations in different groups are to be connected, than where such connection is accomplished by operating both the switches 14 of such stations and the connecting switches 33 individual to the groups to which such stations are normally assigned, and has the added advantage of leaving the group conductors free for other use.

What is claimed is:

1. A telephone system comprising a plurality of stations arranged in groups, each of said stations being normally assigned to a particular group, group conductors for each of said groups, a source of current for said system, resistance means individual to each of said stations to regulate the current supplied to its respective stations, switching means individual to each of said stations to control the association of its stations with conductors of the group to which it is normally assigned and to control the connection of said source of current to its respective station through its respective resistance means, other switching means individual to each of said stations toalso control the connection of said source of current to its respective station through its respective resistance means, and means adapted to extend between said other switching means of stations normally in different groups, whereby a station normally in one group can be disassociated therefrom and transi'erred to an` other group without affecting the strength of current supplied to such station.

2. A telephone system comprising a plurality of stations arranged in groups, group conductors foreach group, a source of current for the system, switching means individual to each station for operatively asso ciating the station and the source of current with the group conductors, group connecting conductors, switching means individual to each group to connect the associated group -conductors to the group connecting conductors, additional switching means individual to each stationv and adapted to connect the source of current to the station, a link circuit for interconnecting the additional switching means thereby interconnecting the associated stations independently of the group connecting conductors, and current regulating means included between the source of current supply and a station by any of the station switching means associated with the station to provide substantially the same amount of current to the station.

3. A telephone system comprising a plurality of stations yarranged in groups; group conductors for each group; a source of current for the system; current regulating means for each station; switching means in dividual to each station for associating the station with the source, the regulating means and group conductors; group connecting conductors; switching means individual to each group `for connecting the associated group conductors with the group connecting conductors, thereby establishing a common connection between all of the stations connected to group coductors; additional switching means individual to each station for associating the station with the source of current and the regulating means; a link circuit coperating therewith for interconnecting any two stations independently of thegroup connecting conductors, said stations receiving substantially the same amount of current as in the common connection.

4. A telephone system comprising a plurality of groups of interconnected stations, current regulating means individual to and associated with each station, a common source of current connected to the regulating means, switching means for interconnecting the groups of stations, means for intercon-l necting any two selectedy stations independently of other stations, and means responsive thereto to maintain thev connection of the selected stations with the -associated regulating means and the common source thereby insuring substantially the same amount of current supplied thereto.

In witness whereof, I hereunto subscribe my name this 15th day of March A. D., 1918.

WLLIAM T. BOOTH. 

